Rheostat



Nov. 13, 1923. 1,474,060

A. E. WALLER RHEOSTAT v Filed Dec. 51, 1920 Ill/6 M770 5 mum-Eli 12 2mm:

13 A flbbomw Q QM,

Patented Nov. 13, 1923.

UNITED STATES PATENT OFFICE.

ALFRED ERNEST WALLER, OF BRONXVILLE, NEW YORK, ASSIGNOR TO WARD A. CORPORATION OF NEW YORK.

RHEOSTAT.

Application filed December 31, 1920.

T a] Z to 710m. it mag l concern:

Be it known that I, ALFRED E. Vanna. a citizen of the United States, residingat Bronxville, in the county of lVestchester and State of New York, have invented certain new and useful,Improvements in Rheostats, of which the following is a specification.

My invention is particularly well adapted for the type of rheostats controlling comparatively large currents of low voltage, such as in rheostats for electroplating and other purposes.

One object of my invention is to produce a rheostat of the above type which will be of comparatively large capacity and small size; another object is to produce a rugged and durable construction; and another object is to produce a simple form of construction economical in manufacture by reason of its simplicity and comparatively small amount or metal required in the contact making and breaking parts.

Another object is to secure ample heat radiating capacity.

One object of my improvement is to produce not only a small sized conveniently n operated rheostatic contact device, but also one which will insure a firm contact over a comparatively large surface area and be rugged in construction. My improved con tact means is a rotary device and compared V with the usual knifeblade switch is superior in insuring firm and adequate contact. is self-aligning and self-cleaning and comparatively slight pressure will close the rheostat contacts and will subject the contact sun faces to a high pressure insuring intimate contact between the surfaces with precision and certainty. Knife switches are easily bent which causes improper and poor contact of the parts; and when they have been i used and become slightly worn. the contact 1 surfaces do not engage well. with the consequent poor contact andoverheating. The knife switch also requires more metal in its construction than is the case with 'my improved switch. These ohjectsahd advantages of my invention. as well as other advantageous features. will be understood from the following description and accord panying drawings which illustrate a preferred embodiment of my invention.

Fig. 1 isa front elevation; Fig. 2 is a side 'tion thereof is a heavy metal bar 8 of brass Serial No. 434,278.

, view, and Fig. 3 is a vertical cross section of one of the switches.

The rheostat comprises two panels 1. 1 in the form of plates of insulating material, the panels being supported in any suitable manner such as by the iron strips or frame pieces 2. On the upper panel is illustrated a controlling switch 3, a volt meter 4 and ammeter 5, as is usual in electroplating apparatus.

The lower panel 1 supports the resistance units 6. which in this instance are in the form of tubular units having a tube of insulating material upon'which arewound the resistance wires of suitable size and length and material to give the resistance required for the particular case. The resistance wires are coated and embedded in insulating material for protection. such as vitreous enamel. These resistance units will be of diii'eren't sizes and otdiiferent: resistance values so as to give the variation and range of control desired. They are supported endwise on the panel 1 by screws 7 which pass through the panel and through the resistance tubes respectively and have a nut and washer 7 at their rear ends for clamping the tubes in position. as shown in Fig. 2. n the face of thelower panel 1 and extending horizontally along the upper poror other suitable material. It has anumher of circular holes through which pass forwardly from the rear. with a suitable amount of clearance space. the screw bolts or studs 9. On the front end of each screw or screw bolt 9 is a nut or collar 10 having a single wing ill). The pitch of the thread of the screws 9 is quite high so that a half turn of the nut 10 will cause considerable axial movement of the nut. When the wing 10 is turned upwardly to the position shown by the left-hand nut in Fig. l and as also shown in Fig. 3. the nut is brought into firm contact with the bar 8 making electrical coiinection'between the screw 9 and the bar ,8 over a large contact area and with a high degree ot pressure. even with comparatively small pressure by the operator on thewing' lO. .l urnim; the. wing 10 to the left and letting it fall to its lower position breaks ion the contact between the nut and the plate.

8 and causes the nut to more rapidly away from the plate to a consideral'ilc distance in about a half revolution of the nut. Stop pins 11 are mounted. on the panel 1" below the switches respectively and are engz-ic'ed by the wings 10 to prevent them from turning beyond a certain liinit.

Secured to the baclc oi. the panel 1 and extendin horizontally alongthe upper portion, is a strip oi insulating material l. Each screw 9 has a rear portion which passes through the strip 1 and also a collar or shoulder 9 which engages the inner t'ace oi the strip 1. Nuts 9 on. the rear threaded portion of the bolt 9 securely clamp the bolt 9 to the strip 1 l lxtendiug horizontally along the lower portion of panel 1 and at the back oi the. panel, is a metal strip At the left-l and end o'l. this strip and enten ilinp; through it and through the panel l" is a terminal connection 19., consisting of a bolt and nuts and washers vaich serves as one oi. the main terminals of the apparatus. At the right ot the panel is another tern'rinal 13, which consists of a bolt. nuts and washers and is mounted on the panel and forms the other main terminal of the appar-tus. FY0111 the main terminal 13 a heavy conductor extends. at the rear of the panel, to and is electrically connected with the metal strip 8 by means of screw bolts 14;. lhese screw bolts have their heads engaging the face of the metal strip 8 and have nuts at their rear ends which serve to engage the conductor from the terminal 13 and also serve to clamp the metal strip 8 and the insulating strip 1 in position on panel 1".

One of the leads from each of the resist ance units 6 is electrically connected to the metal strip 12 at the back of the panel by means of screw bolts 17 These screw bolts extend through the panel 1 and the strip i12 having their heads engaging the face of the panel. while the nuts and washers at the rear of the screw bolts serve to receive the leads from the resistance units and also servo to clamp the strip 12 to the panel. The other leads from each of the resistance units 6 are connected respectively to the screw bolts 9 by being clamped betweenthe nuts 9 In some cases the terminals from two or more oil the resistance units may be connected to one of: the screw bolts and thus may be grouped to glVQ the delired steps of control according to the requirements of each particular case.

In operation and when the wings it)" are swung to their lower position. the circuit through the resistance units open. The swinging of any wing 10 to its pper position as :tor example, the left-hand one of F '1 causes the circuit between its screw t) and the plate 8 to be closed. as above c:-;- plained. and so places one or more resist ance units connected thereto in the main circuit. ill? it be desired to increase the current. another one or more of the win nuts are rotated, to close the particular resistance circuit or circuits desired to give the proper amount oi current. It will be understood that the res ."ance units are of various sizes and resistances and are graduated so that a very large rangeot current control wurcd by closing any one of the wing: nuts and by closing more than one of the wing nuts in ditl'erei'it combinations and groupings as desired.

it will be seen that the construction is very rugged and dural'jile and conveniently manuiactured. and assembled. It is also a simple form of construction and secures a large range of control with conunirutircly tcw switches.

The Form of switch is one which is certain to give a lirin and adequate contact illHiOl' high pressure. The circuit can be closed very quickly by rapidly turniirr the wing nut and it opened quickly. because when the operator torces the wing nut to open the switch. the contact pressure sudilenly releases and by reason of: the high pitch of the thread, the nut mores a. coin siderable distance with a small angular movement. ln order to secure a huge pitch ot the thread on the tiront end oi the screw bolts 9. a double or treble thread may be used and thus secure ample contact and strengl th bet ween the wing nut and the screw bolt. In this particular instance a d uble thread used. The stops ll prevent the wingsv oi? the nuts from turning" beyond their lower position, which prevents the nuts from being taken oil" the. screw bolts and from being misplaced or lost. The construction is preferably made so that the closed position of the nut brings the wing 10 to its upper position. This arrangementliiuits the rotation of the wing nut to about 180 at on side of: the not only and prevents any interference or engagement of the. win; ol" oue nut with the wing of the adjacent nut. it thus permits the nuts to he lo 'ated near together. it: only being necessary to have sufiicicntclearance between the wing); ol one nut and its adjacent not at the left. It thus gives a more compact construction. as without.- the above construction, the nut would have to be placed far enough apart to give. clearaini'e between the wings of two adjacent: nuts when extending toward each other.

h'ly invention may be embodied in various modified forms of? construction and the parts variously related withmit dcpartii'ra" from the scope thereof.

'1. A rhcostat comprising resistance clemcnts. a conducting eleu'ient. a plurality of threadi-ul elements insulated 'troni said conducting elennant. and a plurality of rotatable elements on said threaded elements respectively for connecting and t'llFtCOl'illttflllllfl said threaded elements with said conducting element and thereby connecting and disconnecting said resistance elements in circuit.

2. A rheostat comprising plurality of resistance elements connected to aterminal, a conducting'element, a "Jlurality of threaded elements extending through but electri' cally insulated from said conducting element, said resistance elements being connected respectively to said threaded elements, and rotatable elements on said threaded elements for connecting said threaded elements respectively with said conducting element. r

3. A rheostat comprising a panel, a conducting element on the face of said panel, threaded elements mounted on said panel and extending through said conducting element and insulated therefrom, resistance elements located on the rear of said panel and connected to said threaded elements at the rear of said panel, and rotatable elements on said threaded elements respectively in front of said conducting element for connecting and disconnecting said resistance elements with said conducting element.

4:. A rheostat comprising a panel, a per forated conducting element on the face of said panel, threaded elements projecting forwardly through said perforations, resistance elements connected to said threaded elements, and rotatable elements on said threaded elements in front of said conducting element for connecting and disconnecting said threaded elements respectively to said conducting element.

5. A rheostat comprising a panel, a perforated conducting element on the face of said panel, threaded elements projecting forwardly through said perforations, resistance elements connected to said threaded elements, and rotatable elements on said threaded elements in front of said conduct ing element for connecting and disconnecting saidthreaded elements respectively to said conducting element, said threaded elements having a high pitch.

6. A rheostat comprising a panel, a perforated conducting element on theface of said panel. threaded elements projecting forwardly through said perforationaresistance elements connected to said threaded elements, and rotatable elements on said thread ed elements in front of said conducting element for connecting anddisconnecting said threaded elements respectively to said con ducting element, and stops mounted on said panel for limiting the rotation of saidrotatable elements. 7

7. A rheostat comprising a panel, a perfo ratedconducting element on the face of said panel, threaded elements projecting forwardly through said perforations, resistance elements connected to said threaded elements, and rotatable elements on said threaded elements in front of said conducting element for connecting and disconnecting said threaded elements respectively to said conducting element, said rotatable elements having projecting handles.

8. A rheostat comprising a panel, a perforated conducting element on the face of said panel, threaded elements projecting forwardly through said perforations, resistance elements connected to said threaded elements, and rotatable elements on 'said threaded elements in front of said conducting element for connecting and disconnecting said threaded elements respectively to said conducting element, said rotatable elements having projecting handles, and stops mounted on said panel for limiting the rotation of said rotatable elements When said handles are in their lower position.

9. A rheostat comprising a panel, a plurality of resistance units mounted on the rear of said panel, a perforated conducting element mounted on the face of said panel,

a plurality of threaded elements projecting through said perforations respectively, and a plurality of rotatable elements on said threaded elements respectively for connecting and disconnecting said threaded elements with said conducting element, said resistance units being connected to said threaded elements respectively.

10. A rheostat comprising a panel, a plurality of tubular resistance units mounted endwise on the rear of said panel, a perforated conducting element mounted on the face of said panel, a plurality of threaded elements projecting through said perforations respectively, and a plurality of rotatable elements on said threaded elements respectively for connecting and disconnecting said 106 threaded elements with said conducting ele ment, said resistance units being connected to said threaded elements respectively.

11. A rheostat comprising a panel, a con ducting element on the face of said panel, a 110 second conducting element on said panel, a plurality of resistance elements mounted on said panel between said two elements, threaded elements extending through said first named con ducting element but insulated. 118 therefrom, and rotatable elements on said threaded elements for connecting and disconnecting them respectively with said first named conducting element, said resistance elements being electrically connected be- 110 tween said second named conducting element and said threaded elements respectively.

12. A rheostat comprising a conducting element, a resistance element,a second conducting element insulating from said first 128 named conducting element. said resistance element being connected to said conducting elements respectively, and a coupling device for connecting said conducting elements,

said device comprising a stud and a rotat 130 able collar on said stud, the said collar and stud having an inclined surface engagement.

18. A rheostat comprising a plurality of resistance elements, a conducting element, said resistance elements being connected to said conducting element, a plurality of conducting elements to Which said resistance elements are respectively connected, and a plurality of separately operable coupling devices for electrically connecting said conducting elements respectively with said conducting element, each of said devices comprising astud and a rotatable collar on said stud, the said collar and stud having an inclined surface engagement.

14. A. rheostat comprising a plurality of resistance elements a conducting element said resistance elements being connected to said conducting element, a plurality of conducting elements to which said resistance elements are respectively connected, and a plurality of separately operable coupling devices for electrically connecting said conducting elements respectively With said conducting element, each of said devices comprising a stud and a rotatable collar on said stud the said collar and stud having an inclined surface engagement and. having a high pitch.

ALFRED ERNEST WALTER. 

